org.apache.lucene.index

Class MultiFields

java.lang.Object

org.apache.lucene.index.Fields

org.apache.lucene.index.MultiFields

All Implemented Interfaces:

Iterable<String>

public final class MultiFields
extends Fields

Provides a single Fields term index view over an IndexReader. This is useful when you're interacting with an IndexReader implementation that consists of sequential sub-readers (eg DirectoryReader or MultiReader) and you must treat it as a LeafReader.

NOTE: for composite readers, you'll get better performance by gathering the sub readers using IndexReader.getContext() to get the atomic leaves and then operate per-LeafReader, instead of using this class.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields inherited from class org.apache.lucene.index.Fields

EMPTY_ARRAY

Constructor Summary

Constructors

Constructor and Description
MultiFields(Fields[] subs, ReaderSlice[] subSlices) Sole constructor.

Method Summary

Modifier and Type	Method and Description
Iterator<String>	iterator() Returns an iterator that will step through all fields names.
int	size() Returns the number of fields or -1 if the number of distinct field names is unknown.
Terms	terms(String field) Get the Terms for this field.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

MultiFields

public MultiFields(Fields[] subs,
                   ReaderSlice[] subSlices)

Sole constructor.

Method Detail

iterator

public Iterator<String> iterator()

Description copied from class: Fields

Returns an iterator that will step through all fields names. This will not return null.

Specified by:

iterator in interface Iterable<String>

Specified by:

iterator in class Fields

terms

public Terms terms(String field)
            throws IOException

Description copied from class: Fields

Get the Terms for this field. This will return null if the field does not exist.

Specified by:

terms in class Fields

Throws:

IOException

size

public int size()

Description copied from class: Fields

Returns the number of fields or -1 if the number of distinct field names is unknown. If >= 0, Fields.iterator() will return as many field names.

Specified by:

size in class Fields